Drive means for a weft carrying device in circular looms

ABSTRACT

Drive means for a weft-carrying device in circular looms wherein the connection between the drive means and the driven means carried by the weft-carrying device, is a frictional engagement.

United States Patent Armand Malchair [51] Int. 37/00 HerstaLBelgium [50] Field ofSearch............................................ 139/12, 1, [21] AppLNo. 732,329

[72] Inventor [22] Filed May 27,1968 [45] Patented Feb. 16,1971

[56] References Cited UNITED STATES'PATENTS 5/1915 Rhomoser.....

[73] Assignee Peltzer 8: Fils S. A., societe anonyme [32] Priority 1,583,543 5/1926 Fredrickson..................

Primary ExaminerHenry S. Jaudon Attorney- Richards and Geier ABSTRACT: Drive'means for a weft-carrying device in circular looms wherein the connection between the drive means Verviers, Belgium June 20, 1967 Belgium 700,194

[54] DRIVE MEANS FOR A WEFT CARRYING DEVICE IN CIRCULAR LOOMS 7 Claims, 6 Drawing Figs.

and the driven means carried by the weft-carrying device, is a frictional engagement.

PATENTEIJFEBISIHYI v 35632-79 SHEETIUFZ INVENTOR.

Malchcu'r PATENTED FEB 1 6 I971 31563279 SHEET 2 UF 2 INVENTOR. BY A, MQZchaL'r A T RNESS 1 it nnrva MEANS FOR A wsr'r. cxnnvmo DEVICE IN CIRCULAR LOOMS V This invention pertains to drive means forfa weft-carrying device in circular looms. More particularly,the mechanism according to the invention will be applied to such looms having a shuttle without any pirn, i.e., looms in which the shuttle has essentially the function of a weft puller, the weft yarn weft yarn and without causing any detrimental effect in the provision of a perfectly regular weft, so that the rotating speed of thefloom may be kept at a maximum to provide a maximum production and, in any case, a rotating speed higher than, all other things being the same, that generally reached in' straight looms owing to the increasing beating rhythm of the shuttle picks.

Various mechanisms have already been proposed either to rotate the pirn-carrying shuttle or to rotate the shuttle conditioned to function as a weft-pulling device.

Some of the proposed solutionsare quite acceptable, but only up to a maximum rotation speed of the loom which does not meet any more the present requirements of the weavers.

. This limitation results either from the design itself of the suggested mechanism or from the used means or members which, above a certain speed limit, are introducing interferences in the loom either the packing of the warp yarns or by detrimental friction effects on the yarns orbythe generalization of dynamic effects causing undue vibrations or by difficulties to keep the tensions constant and mandatory on all the warp yarns so that after having tightened the weft picks,,the weft yarns of the fabric are perfectly regular, any defect being rapidly visible and causing the rejection of the fabric.

The weft-pulling device'according to 'the invention takes these different requirements into consideration and it brings about a relatively simple solution which, in the experimental loom, has appeared to be satisfactory asregards the highest required rotation speeds. This mechanism is not only simple, but it introduces also very flexible driving means capable of absorbing or neutralizing any incidental stress, while providing also a complete protection for the warp yarns as well as for the weft yarns, even at the highest speeds of theloom. Thus, the invention discloses a drive means for a weft-carrying device in circular looms of the type comprising a stationary part, a moving equipment rotatable around the axis of the loom, a fell line, shedding means and at least one weft-carrying device movable along a circular path between said fell line and said shedding means, said drive means comprising the combination of a special toothed wheel, having radially extending arms equally spaced, carried on said weft-pulling device; a positive guiding means for the said weft-pulling device, said means comprising at least a grooved roller engaged between two annular guides fixed to said stationary partian annular stationary track, the upper surface of which being made of a material having a good adherence and, between the latter and the said special wheel carried by the weft-pulling device, an intermediate mechanism adjustably mounted upon the rotating equipment of the loom, said intermediate mechanism comprising at least a friction wheel in contact with said stationary track, at least a means, preferably two driving friction wheels, in contact with the special wheel carried by the weft-pulling device, and kinematic means allowing the-first friction wheel in contact with the stationary track to transfer its rotational I movement to the other friction wheels, i.e., also to the special wheel carried by the weft-pulling device.

This mechanism comprises the combination of three essential parts, namely the stationary guiding track, the shuttle or the weft-pulling device proper and the intermediate mechanism between the said track and the said shuttle or weft-pulling device. l

The driving track is provided by a ring bearing upon the stationary part of the loom and the driving wheel of the rotating system carried by the said intermediate mechanism engaging said ring. a

The particular feature of this guiding and driving track lies in the fact that it presents a generally perfectly smooth rolling surface having a slightly conical shape and it is conditioned, in cooperation with the wheel of the intermediate mechanism it must drive, so that the contact surfaces or at least one of them are relatively resilient to produce a good adherence. The term good adherence is used to mean that the said surfaces are such that the wheel driven by the said guiding track rolls over the latter substantially without sliding under the normal operating conditions of the loom, a sliding effect being however possible in case of accidental resistance, thereby introducing a first important safety feature in the said weftpulling device.

The shuttle or the weft-pulling device proper may have any suitable shape, dimensions and design. However, according to the invention, this shuttle or weft-pulling device is essentially characterized in that it carries an axis upon which is mounted an idle wheel meshing the warp yarns. This wheel is special in construction in that it comprises a hub and equally spaced radial arms. Thus, this wheel has the configuration of a rimless spoke wheel and it is like a disc having very deep peripheral grooves equally spaced angularly. These teeth and grooves are provided so as to present no sharp edges for guiding correctly the radial warp yarns successively encountered without damaging or stressing them detrimentallly.

It is of course apparent that this shuttle or weft-pulling device will be provided with such positive guiding means so as to produce a circular path perfectly concentric with the axis of the loom orthesaid annular guiding and driving track.

Finally, the intermediate mechanism between the said track and the said shuttle or weft-pulling device comprises substantially a small frame carrying the friction wheel kept in permanent Contact with the said track, two friction wheels kept in permanent contact symmetrically and on both sides of the said special wheel with radial arms carried by the shuttle or the weft-pulling device and a kinematic connection between the axes of said different wheels to impart a continuous rotating movement thereto. The said frame is integral with the large rotating crown of the circular loom so that, by rotating about the axis of the loom, said casing induces the continuous rotation of the different wheels carried thereby. The same casing functions also as a carrier for a guiding block for the warp yarns, said block being disposed tangentially to the said special wheel carried by the shuttle or the weft-pulling device near the bottoms of the teeth of said wheel.

It is of course apparent that the object of the invention is not strictly limited to all these characteristic arrangements as described, it being possible to combine and to fit them and possibly substituting equivalent arrangements or members therefor without departing from the scope of the invention.

Thus, it is only by way of example that an embodiment will be set forth hereafter with more details with reference to the enclosed drawings in which:

FIG. 1 is a schematical side elevation of the device accord ing to the invention;

FIG. 2 is a view according to arrow F of FIG. 1;

FIGS. 3, 4 and 5 are sections taken, respectively, on the lines III-III, IV-IV and V-V of FIG. 2;

FIG. 6 shows another embodiment of the guiding means of the weft-pulling device.

As known, this loom has a stationary part represented diagrammatically in l and the moving equipment shown in 2. The stationary part 1 comprises a solid frame 3 carrying the heald frames, the driving device for the heald frames, the warp beam support, the warp beam unwinding stand and generally all the mechanisms and members necessary for unwinding the warp yarns, settling the shed and the like up to the weaving ring shown diagrammatically in 4.

The drive means according to the invention comprise an annular track 5 formed by a continuous plastic strip born by and fastened to an annular seat 6 carried by said stationary part 1, said track having a conical upper surface 7, said track 5 being located under the plane containing the circular trajectory of at least one shuttle or weft pulling device 8. Said drive means further comprise an intermediate mechanism, between said track 5 and said weft-pulling device 8.

This intermediate mechanism comprises a frame 9 carried by a bracket 10 mounted on said moving part 2, which rotates around the axis of the loom when the latter is operated. Frame 9 carries a shaft 11 upon which are wedged a friction wheel 12 and a toothed wheel 13. Said shaft 32 extends parallely to said upper surface 7 of track 5. The friction wheel 12 has a width substantially equal to that of track 5 and contacts the latter. The pressure of wheel 12 on track 5 may be adjusted by the bolt-and-slot device schematically shown in 14. The frame 9 carries the brackets 15 and 16 fastened thereto by means of screws 17 and 18, each said brackets carrying a shaft 19 and 20, respectively. Upon each said shaft are wedged a friction wheel 21 and 22 respectively, as well as a toothed wheel 23 and 24 respectively. These wheels are so disposed that the three toothed wheels 13, 23 and 24 are coplanar and intermeshing, while friction wheels 21 and 22 are coplanar and in peripheral contact with a special wheel 25, carried by a shaft 26 and havinga hub 27, and radial arms 28, carried by a part of said shuttle or weft-pulling device 8.

The frame 9 is topped by a strip-shaped shoe 29, the ends of which curving downwardly, said shoe being fixed to frame 9 by lugs 30, so that the flat portion of said shoe extends parallely to said surface 7 of track 5, in the immediate vicinity of and slightly underneath hub 27. The level of the upper surface of said shoe corresponds to that of correctly positioned warp threads of the lower shed, thus allowing a free passage of the weft-drawing device 8.

The shuttle or weft-pulling device 8 is of a known type, such as described in detail in applicant's U.S. Pat. No. 3,439,714 lt substantially comprises a body 31 carrying a platform 32, on which are rotatably mounted a first set of grooved rollers 33 and a second set of such rollers 34 mounted in staggered relationship with the former. This weft-pulling device may be supported, via wheels 35 rotatable on shafts 36, by annular parallel guides 37 and 38 or by upper and lower blades 39 and 40 extending from annular rods 37 and 38 respectively, the ends of said blades cooperating with upper and lower grooves 41 and 42 of a plate 43 integral with said body 31. To check the motion of the platform 32, the external edge 44 and the internal edge 45 of the upper and lower grooves 42 and 43 respectively are given a height greater than that of the remaining edges 46 and 47. The device thus described operates as follows. When the loom is to be operated, the moving equipment 2 is rotated around the axis of the loom, thus also said intermediate mechanism and the friction wheel 12 thereof. Said wheel 12 is thus rotated due to its frictional engagement with stationary track 5. Toothed wheel 13 also rotates and drives toothed 'wheels 23 and 24, thus also friction wheels 21 and 22. The friction wheel located behind wheel 25 with respect to the direction of rotation of the moving assembly 2, say wheel 43, exerts a radial pressure on each arm 28 successively, as wheel 25 rotates due to said pressure and the fact that its radial arms 28 successively mesh with the warp threads of the lower shed.

It will be observed that the connection between the shuttle or the weft-pulling device 8, on one hand, and the driving means thereof, on the other hand, is made through friction surfaces or friction stresses, the latter being such that the movements are transmitted by rolling without any detrimental sliding stress when the loom operates normally, such incidental sliding movements being however possible as safety means in case of incidental resistance encountered by the moving equipment of the loom.

The different friction surfaces may be improved by making the tracks and/or the wheels of a relatively flexible material having a good adherence or by coatings or surface treatments of the contact surfaces to provide a good adherence between the friction surfaces.

The invention relates to any kmd of shuttle mechanism or weft-pulling device using one or several characteristics disclosed herein, as well as to any loom or loom part using such characteristics.

I claim:

1. A drive means for a weft-carrying device in circular looms of the type comprising a stationary part, a moving equipment rotatable around the axis of the loom, a fell line, shedding means and at least one weft-carrying device movable along a circular path between said fell line and said shedding means, said drive means comprising the combination of a special toothed wheel having radially extending equally spaced arms and carried on said weft-carrying device; positive guiding means for said weft-carrying device, said guiding means comprising at least two annular guides fixed to said stationary part; an annular stationary track the upper surface of which has a layer of material having a good adherence and, between the track and said special wheel, an intermediate mechanism adjustably mounted upon the moving equipment of the loom, said intermediate mechanism comprising at least one friction wheel in contact with said track, two driving friction wheels in contact with said special wheel and motion transmitting means between the friction wheel which is in contact with the track and the driving friction wheels which are in contact with the special wheel.

2. A drive means in accordance with claim 1, wherein said guiding means further comprise a grooved roller rotatably carried by said weft-carrying device and engaged between said two annular guides.

3. A drive means in accordance with claim 2, comprising separate series of blades carried by each of the two annular guides, said guiding means further comprising a block carried by said weft-carrying device and having two oppositely facing grooves, each of said grooves facing a separate series of said blades and successively engaging the ends of the blades as the weft-carrying device moves along its circular path.

4. A drive means in accordance with claim 3, wherein said block is a wooden plate integral with said weft-carrying device, said grooves being located on opposite sides of said plate and consisting of an upper groove and a lower groove, the external edge of the upper groove and the internal edge of the lower groove having a length higher than that of the two other edges of said grooves.

5. A drive means in accordance with claim 1, wherein the driving friction wheels which are in contact with the special wheel have contact surfaces consisting of a plastic material.

6. A drive means in accordance with claim 1, wherein said intermediate mechanism is adjustably mounted upon said moving equipment by a frame, a guiding block carried by said frame and guiding the lower warp yarns of a shed as the weftcarrying device progresses therethrough.

7. A drive means in accordance with claim 6, wherein said guiding block-has a flat central portion extendingparallel to the upper surface of said stationary track and two ends curving toward the track, said flat central portion being located at the level of the upper portions of the driving friction wheels which are in contact with the special wheel. 

1. A drive means for a weft-carrying device in circular looms of the type comprising a stationary part, a moving equipment rotatable around the axis of the loom, a fell line, shedding means and at least one weft-carrying device movable along a circular path between said fell line and said shedding means, said drive means comprising the combination of a special toothed wheel having radially extending equally spaced arms and carried on said weft-carrying device; positive guiding means for said weft-carrying device, said guiding means comprising at least two annular guides fixed to said stationary part; an annular stationary track the upper surface of which has a layer of material having a good adherence and, between the track and said special wheel, an intermediate mechanism adjustably mounted upon the moving equipment of the loom, said intermediate mechanism comprising at least one friction wheel in contact with said track, two driving friction wheels in contact with said special wheel and motion transmitting means between the friction wheel which is in contact with the track and the driving friction wheels which are in contact with the special wheel.
 2. A drive means in accordance with claim 1, wherein said guiding means further comprise a grooved roller rotatably carried by said weft-carrying device and engaged between said two annular guides.
 3. A drive means in accordance with claim 2, comprising separate series of blades carried by each of the two annular guides, said guiding means further comprising a block carried by said weft-carrying device and having two oppositely facing grooves, each of said grooves facing a separate series of said blades and successively engaging the ends of the blades as the weft-carrying device moves along its circular path.
 4. A drive means in accordance with claim 3, wherein said block is a wooden plate integral with said weft-carrying device, said grooves being located on opposite sides of said plate and consisting of an upper groove and a lower groove, the external edge of the upper groove and the internal edge of the lower groove having a length higher than that of the two other edges of said grooves.
 5. A drive means in accordance with claim 1, wherein the driving friction wheels which are in contact with the special wheel have contact surfaces cOnsisting of a plastic material.
 6. A drive means in accordance with claim 1, wherein said intermediate mechanism is adjustably mounted upon said moving equipment by a frame, a guiding block carried by said frame and guiding the lower warp yarns of a shed as the weft-carrying device progresses therethrough.
 7. A drive means in accordance with claim 6, wherein said guiding block has a flat central portion extending parallel to the upper surface of said stationary track and two ends curving toward the track, said flat central portion being located at the level of the upper portions of the driving friction wheels which are in contact with the special wheel. 